2 .\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 .\" Copyright (c) 2017 Kyle Kneitinger
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6 .\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
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36 .Nd library for creating, destroying and modifying ZFS boot environments
41 .Ft "libbe_handle_t *hdl" Ns
42 .Fn libbe_init "const char *be_root"
45 .Fn libbe_close "libbe_handle_t *hdl"
48 .Fn be_active_name "libbe_handle_t *hdl"
51 .Fn be_active_path "libbe_handle_t *hdl"
54 .Fn be_nextboot_name "libbe_handle_t *hdl"
57 .Fn be_nextboot_path "libbe_handle_t *hdl"
60 .Fn be_root_path "libbe_handle_t *hdl"
63 .Fn be_is_auto_snapshot_name "libbe_handle_t *hdl" "const char *snap"
66 .Fn be_create "libbe_handle_t *hdl" "const char *be_name"
69 .Fn be_create_depth "libbe_handle_t *hdl" "const char *be_name" "const char *snap" "int depth"
72 .Fn be_create_from_existing "libbe_handle_t *hdl" "const char *be_name" "const char *be_origin"
75 .Fn be_create_from_existing_snap "libbe_handle_t *hdl" "const char *be_name" "const char *snap"
78 .Fn be_rename "libbe_handle_t *hdl" "const char *be_old" "const char *be_new"
81 .Fn be_activate "libbe_handle_t *hdl" "const char *be_name" "bool temporary"
83 .Fn be_destroy "libbe_handle_t *hdl" "const char *be_name" "int options"
86 .Fn be_nicenum "uint64_t num" "char *buf" "size_t bufsz"
88 .\" TODO: Write up of mount options
90 .\" BE_MNT_FORCE = 1 << 0,
91 .\" BE_MNT_DEEP = 1 << 1,
94 .Fn be_mount "libbe_handle_t *hdl" "char *be_name" "char *mntpoint" "int flags" "char *result"
97 .Fn be_mounted_at "libbe_handle_t *hdl" "const char *path" "nvlist_t *details"
100 .Fn be_unmount "libbe_handle_t *hdl" "char *be_name" "int flags"
103 .Fn libbe_errno "libbe_handle_t *hdl"
106 .Fn libbe_error_description "libbe_handle_t *hdl"
109 .Fn libbe_print_on_error "libbe_handle_t *hdl" "bool doprint"
112 .Fn be_root_concat "libbe_handle_t *hdl" "const char *be_name" "char *result"
115 .Fn be_validate_name "libbe_handle_t *hdl" "const char *be_name"
118 .Fn be_validate_snap "libbe_handle_t *hdl" "const char *snap"
121 .Fn be_exists "libbe_handle_t *hdl" "char *be_name"
124 .Fn be_export "libbe_handle_t *hdl" "const char *be_name" "int fd"
127 .Fn be_import "libbe_handle_t *hdl" "const char *be_name" "int fd"
130 .Fn be_prop_list_alloc "nvlist_t **prop_list"
133 .Fn be_get_bootenv_props "libbe_handle_t *hdl" "nvlist_t *be_list"
136 .Fn be_get_dataset_props "libbe_handle_t *hdl" "const char *ds_name" "nvlist_t *props"
139 .Fn be_get_dataset_snapshots "libbe_handle_t *hdl" "const char *ds_name" "nvlist_t *snap_list"
142 .Fn be_prop_list_free "nvlist_t *prop_list"
145 interfaces with libzfs to provide a set of functions for various operations
146 regarding ZFS boot environments including "deep" boot environments in which
147 a boot environments has child datasets.
149 A context structure is passed to each function, allowing for a small amount
150 of state to be retained, such as errors from previous operations.
152 may be configured to print the corresponding error message to
154 when an error is encountered with
155 .Fn libbe_print_on_error .
157 All functions returning an
159 return 0 on success, or a
161 errno otherwise as described in
166 function takes an optional BE root and initializes
169 .Vt "libbe_handle_t *"
173 If a BE root is supplied,
175 will only operate out of that pool and BE root.
176 An error may occur if:
178 .It /boot and / are not on the same filesystem and device,
179 .It libzfs fails to initialize,
180 .It The system has not been properly booted with a ZFS boot
183 fails to open the zpool the active boot environment resides on, or
185 fails to locate the boot environment that is currently mounted.
190 function frees all resources previously acquired in
192 invalidating the handle in the process.
196 function returns the name of the currently booted boot environment.
197 This boot environment may not belong to the same BE root as the root libbe
202 function returns the full path of the currently booted boot environment.
203 This boot environment may not belong to the same BE root as the root libbe
208 function returns the name of the boot environment that will be active on reboot.
212 function returns the full path of the boot environment that will be
217 function returns the boot environment root path.
220 .Fn be_is_auto_snapshot_name
221 function is used to determine if the given snapshot name matches the format that
224 function will use by default if it is not given a snapshot name to use.
227 if the name matches the format, and
233 function creates a boot environment with the given name.
234 The new boot environment will be created from a recursive snapshot of the
235 currently booted boot environment.
239 function creates a boot environment with the given name from an existing
241 The depth parameter specifies the depth of recursion that will be cloned from
242 the existing snapshot.
243 A depth of '0' is no recursion and '-1' is unlimited (i.e., a recursive boot
247 .Fn be_create_from_existing
248 function creates a boot environment with the given name from the name of an
249 existing boot environment.
250 A recursive snapshot will be made of the origin boot environment, and the new
251 boot environment will be created from that.
254 .Fn be_create_from_existing_snap
255 function creates a recursive boot environment with the given name from an
260 function renames a boot environment without unmounting it, as if renamed with
263 argument were passed to
269 function makes a boot environment active on the next boot.
272 flag is set, then it will be active for the next boot only, as done by
274 Next boot functionality is currently only available when booting in x86 BIOS
279 function will recursively destroy the given boot environment.
280 It will not destroy a mounted boot environment unless the
285 .Dv BE_DESTROY_ORIGIN
290 function will destroy the origin snapshot to this boot environment as well.
296 in a traditional ZFS humanized format, similar to
297 .Xr humanize_number 3 .
298 This function effectively proxies
304 function will mount the given boot environment.
309 a mount point will be generated in
317 it should be large enough to accommodate
319 including the null terminator.
320 the final mount point will be copied into it.
331 function will check if there is a boot environment mounted at the given
337 it will be populated with a list of the mounted dataset's properties.
338 This list of properties matches the properties collected by
339 .Fn be_get_bootenv_props .
343 function will unmount the given boot environment.
359 .Fn libbe_error_description
360 function returns a string description of the currently set
365 .Fn libbe_print_on_error
366 function will change whether or not
368 prints the description of any encountered error to
375 function will concatenate the boot environment root and the given boot
376 environment name into
381 function will validate the given boot environment name for both length
382 restrictions as well as valid character restrictions.
383 This function does not set the internal library error state.
387 function will validate the given snapshot name.
388 The snapshot must have a valid name, exist, and have a mountpoint of
390 This function does not set the internal library error state.
394 function will check whether the given boot environment exists and has a
397 This function does not set the internal library error state, but will return
398 the appropriate error.
402 function will export the given boot environment to the file specified by
404 A snapshot will be created of the boot environment prior to export.
408 function will import the boot environment in the file specified by
414 .Fn be_prop_list_alloc
415 function allocates a property list suitable for passing to
416 .Fn be_get_bootenv_props ,
417 .Fn be_get_dataset_props ,
419 .Fn be_get_dataset_snapshots .
420 It should be freed later by
421 .Fa be_prop_list_free .
424 .Fn be_get_bootenv_props
425 function will populate
429 of boot environment names paired with an
432 The following properties are currently collected as appropriate:
433 .Bl -column "Returned name"
434 .It Sy Returned name Ta Sy Description
436 .It name Ta Boot environment name
437 .It mounted Ta Current mount point
438 .It mountpoint Ta Do mountpoint Dc property
439 .It origin Ta Do origin Dc property
440 .It creation Ta Do creation Dc property
441 .It active Ta Currently booted environment
442 .It used Ta Literal Do used Dc property
443 .It usedds Ta Literal Do usedds Dc property
444 .It usedsnap Ta Literal Do usedrefreserv Dc property
445 .It referenced Ta Literal Do referenced Dc property
446 .It nextboot Ta Active on next boot
455 returned values will always be present.
456 All other properties may be omitted if not available.
459 .Fn be_get_dataset_props
460 function will get properties of the specified dataset.
462 is populated directly with a list of the properties as returned by
463 .Fn be_get_bootenv_props .
466 .Fn be_get_dataset_snapshots
467 function will retrieve all snapshots of the given dataset.
469 will be populated with a list of
471 exactly as specified by
472 .Fn be_get_bootenv_props .
475 .Fn be_prop_list_free
476 function will free the property list.
478 Upon error, one of the following values will be returned:
479 .Bl -dash -offset indent -compact
527 and its corresponding command,
529 were written as a 2017 Google Summer of Code project with Allan Jude serving
531 Later work was done by
532 .An Kyle Evans Aq Mt kevans@FreeBSD.org .